This invention relates to stuffing boxes and its object is to prevent escape of gases from a container out of which a shaft projects while at the same time permitting movements of the shaft apart from its normal rotary movements around its axis. Thus in a screw type conveyer dealing with hot materials liable to give off hot gas, the screw is located in a housing through which a driving shaft projects for driving the screw. The screw may be many feet long and can have somewhat gyratory or whipping movements and therefore some clearance must be provided between the driving shaft and the housing wall so that hot gases can escape.